1. Technical Field
The embodiments described herein relate to semiconductor integrated devices and, more particularly, to a fusion memory device composed of memory devices that exhibit different functions and a data processing system using the same.
2. Related Art
Memory device can be classified into a volatile memory devices and a non-volatile memory devices. The volatile memory devices include random access memories (RAM) which data stored therein are erased when the power is off. Non-volatile memory devices include read only memories (ROM) which data stored therein is retained when power is off. Typically, a dynamic random access memory (DRAM) is regarded as the RAM and a flash memory device is regarded as the ROM.
DRAMs operate at relatively high speeds due to lower power consumption and simple random access. However, DRAMs require carrying out periodic refresh operations due to their volatile properties and require an increased capacitor capacity due to demand for high charge storage.
Meanwhile, flash memory devices readily stores data at high capacities due to a relatively high integration and flash memories do not require refresh operations due to their non-volatile properties. However, flash memories requires operation voltages that a relatively higher than the power voltage due to the two-layered stack gate structure. Accordingly, flash memories oftentimes require separate voltage boosting circuits for generating the desired program and erase voltages. Furthermore, since it is difficult to randomly access, data is programmed at a page unit, and thereby operating speeds of flash memories are often relatively slow.
Currently, due to market demands, semiconductor memory devices are gradually scaled down more and more. It is a market trend to embody a system on chip (SOC) that the functional blocks having various functions are integrated on one-chip. A fusion memory device is an exemplary SOC.
The fusion memory device is a compound memory device that may contain various different types of memory devices such as having memory chips that have different properties or have non-memory chips which are embedded into a basic memory device together with logic devices. That is, the fusion memory is regarded as a system memory that also provides software suitable to the system specification. A fusion memory device composed of a flash memory device and a static RAM (SRAM) together with a logic device may be integrated into a one-chip design depending on how complex and how high performance the digital electronic appliances needs.
Therefore, flash memory device may require a DRAM which is a representative volatile memory device and a flash memory device which is a non-volatile memory device to be integrated in one-chip. However, the DRAM and the flash memory device have distinctly different operation voltages and different driving operational modes such that the different driving circuits are required. Furthermore, since they have different device structures, when they are integrated on one semiconductor substrate, they necessarily must be fabricated by using separately distinct fabrication processes.